Overall, 1061 potentially eligible participants were identified, of whom 709 (66.8%) were ineligible or did not want to participate (figure). In total 352 (33.2%) patients were randomised: 116 to advice and exercise, 117 to advice and exercise plus true acupuncture, and 119 to advice and exercise plus non-penetrating acupuncture. Thirty seven physiotherapy centres recruited at least one patient (maximum 29 per site). Baseline characteristics of participants (mean age 63 years, 61% women) were similar between the groups (table 1).
| Table 1 Baseline characteristics of participants, by treatment group. Values are numbers (percentages) of participants unless stated otherwise |
Those patients who were screened but not randomised (n=709) were slightly older than those randomised (65 v 63 years), but both groups had 61% of women. Treatment allocation and recruitment characteristics were similar between the higher (≥18 patients; n=177 patients) and the lower (≤17 patients; n=175 patients) recruiting centres (data not shown).
Four participants in the advice and exercise group and two in the advice and exercise plus non-penetrating acupuncture group withdrew permission for further contact in the period up to the six months' follow-up. In the 346 eligible for contact at six months the response rate was 94% for advice and exercise, 93% for advice and exercise plus true acupuncture, and 97% for advice and exercise plus non-penetrating acupuncture. Nineteen participants did not return the questionnaire at six months. Non-responders were more likely to be men (47% v 39%), to be younger (mean age 60 v 63 years), and to have slightly lower baseline scores for pain and function (pain: 8.7 v 9.2, function: 27.8 v 30.5).
Treatments were in line with the study protocols. A few participants violated the protocol: three in the advice and exercise group and two in the advice and exercise plus non-penetrating acupuncture group. No adverse events occurred in the advice and exercise group or in the advice and exercise plus non-penetrating acupuncture group. Five adverse events were reported for participants receiving true acupuncture (pain, sleepiness, fainting, nausea, and swelling around the treated knee).
The median (range) number of treatment sessions was in line with the study protocols: 6 (1-9) in the advice and exercise group, 7 (4-9) in the advice and exercise plus true acupuncture group, and 7 (1-8) in the advice and exercise plus non-penetrating acupuncture group. In both acupuncture groups the acupuncture treatment was used in a median of six sessions. The de qi sensation was reported at least once for 95 (83%) participants receiving true acupuncture and 65 (55%) receiving non-penetrating acupuncture. Of these, 67 (71%) and 29 (45%) reported de qi during at least half of their treatment sessions.
Intervention credibility and exercise compliance
Table 2 summarises treatment credibility two weeks after treatment started. Participants receiving either acupuncture intervention were significantly more confident that treatment could help their knee problem than those receiving advice and exercise alone.
| Table 2 Outcome and credibility of treatment* at two weeks. Values are numbers (percentages) of participants |
Most participants had treatment sessions that included supervised exercises (85% for advice and exercise, 77% for advice and exercise plus true acupuncture, and 78% for advice and exercise plus non-penetrating acupuncture) and a home exercise programme (89%, 91%, and 95%). Self reported compliance with exercise at two weeks was 63%, 70%, and 64% (table 3). Compliance remained above 50% in each group over the 12 months' follow-up.
| Table 3 Compliance with exercise at two weeks. Values are numbers (percentages) of participants unless stated otherwise |
Outcome measures
At six months no statistically significant differences were found in change on the pain subscale from baseline between the groups receiving acupuncture in addition to advice and exercise compared with the group receiving advice and exercise alone (table 4).
| Table 4 Change in pain and function scores.* Values are means (standard deviations) unless stated otherwise |
At six weeks the advice and exercise plus non-penetrating acupuncture group reported small but significantly greater improvements in pain than did the advice and exercise group (mean difference 0.88, 95% confidence interval 0.0 to 1.8). At 12 months no statistically significant differences were found between the groups (table 4). At two weeks statistically significant trends were found in favour of better global outcome for each of the acupuncture groups compared with the advice and exercise alone group (table 5).
| Table 5 Global assessment at follow-up. Values are numbers (percentages) of participants unless stated otherwise |
No other statistically significant differences were found in the changes in function scores, global assessment, or response status according to the OMERACT-OARSI criteria between the three groups at any follow-up points, or in the adjusted analyses (tables 5 and 6).
| Table 6 Response to criteria from the outcome measures in Rheumatology and Osteoarthritis Research Society international initiative at follow-up. Values are numbers (percentages) of participants unless stated otherwise |
Statistically significant differences were found between the groups in pain intensity and unpleasantness (table 7). The results at two and six weeks for pain intensity and at six weeks for change in pain unpleasantness favoured both groups receiving acupuncture. The results at six and 12 months for both pain intensity and pain unpleasantness favoured the group receiving advice and exercise plus non-penetrating acupuncture. Satisfaction with care was significantly greater for participants receiving advice and exercise plus non-penetrating acupuncture than for those receiving advice and exercise alone (table 8). No statistically significant differences were seen between advice and exercise plus true acupuncture and advice and exercise plus non-penetrating acupuncture for any other of the outcomes measured (data not shown).
| Table 7 Change in knee pain and function and psychological measures at follow-up. Values are means (standard deviations) unless stated otherwise |
| Table 8 Change in satisfaction with care at follow-up. Values are numbers (percentages) of participants |
Exploratory subgroup analyses showed no significant differences in change scores for pain or function between participants in the advice and exercise plus true acupuncture group reporting de qi during more than 50% of treatment sessions compared with those who reported de qi less often. Those with severe pain or disability at baseline showed similar change scores in each of the treatment groups (data not shown). No significant differences were found between groups in the number of reported general practitioner consultations over six months (advice and exercise 25%, advice and exercise plus true acupuncture 19%, and advice and exercise plus non-penetrating acupuncture 20%) or in the use of non-steroidal anti-inflammatory or simple analgesics.